Bluetooth Low Energy (BLE) is a wireless personal area network technology designed and marketed by the Bluetooth Special Interest Group aimed at novel applications, in particular for the fields of healthcare, fitness, security and home entertainment. Compared to ‘classic’ or ‘conventional’ Bluetooth’ BLE is intended to provide considerably reduced power consumption and cost while maintaining a similar communication range.
With classic BLE systems at least a pair of BLE devices, one of which denoted as a peripheral and the other one of which denoted as a hub, are able to establish a communication link. Typically, the peripheral device advertises or broadcasts while the hub scans. Once the hub identifies a suitable peripheral device it requests a connection, pairs with the peripheral device and takes control over the peripheral device. At that time, the peripheral device stops advertising and communication becomes ‘closed’ so that communication is solely established between the hub and the peripheral device. For implementation of such a standard method, a complete BLE firmware stack and hardware must be implemented for both BLE devices. In addition, once the communication between the pair of BLE devices has been established the communication takes place point-to-point. It is only visible to the hub and to the connected peripheral device.
Bluetooth Low Energy communication may also be established by a different mode, namely by non-connectable undirected advertising, in short ‘advertising mode’. There, the peripheral device only and exclusively advertises and is unwilling and/or unable to pair or to connect with the hub device. A drawback of this communication protocol is that there is no way for the peripheral device to get knowledge whether a broadcast packet or message has been correctly received by a hub device. Moreover, the peripheral device does not get any information as to which of a multiplicity of available hub devices actually received or processed the previously broadcast packet or message. Another drawback is that the peripheral device is unable to get and to process any feedback or instructions by way of which its further broadcasting behavior could be modified. In addition, the peripheral is unable to receive programming or re-programming instructions wirelessly, e.g. at power up or in situ. It may never act as a hub or as a receiver.